To be honest I think your always better off going to a custom exhaust place, you can tell them then exactly the loudness your after etc, problem with alot of these off the peg aftermarket exhausts is what you have found out. I'm not keen on loud exhaust although I love the exhaust note on the Z4 but settles down nicely when cruising,

Fitted the Cobra standard cat back ( not full) - I think it's the BM17 - on our M44 1.9 earlier this year. We think it's great but at our age maybe the hearing deterioration is dumming it down. The tone will change as it carbon layers.
Rich P fitted the same to his M44 about the sametime and thought it too loud so he removed it.
Down to personal preference I'd advise you give it a bit of time to get used to it - it either grows on you or deafness takes over

Last edited by Jonco on Fri 28 Jun, 2013 09:30, edited 1 time in total.

I sometimes think they sound noisier because you are sat in a 2-seater, soft-top car where the tip of the exhaust is closer to your ears. Also, apart from a thin bit of carpet behind the seats and in the boot, there isn’t much in the way of sound insulation. Probably in a 4-seater, hard-top saloon it wouldn’t be as bad. On the Youtube video of the Cobra exhaust, it doesn’t sound too noisy.

I had a stainless steel back box fitted, and it WAS alarmingly loud, touching on a bit embarrassing at first. It's because it so new, stainless steel and a thin material, doubled with the fact you basically sit on the tip. I must say though it has calmed down a fair bit, and has a deeper rasp compared to its original boomy scream! Thankfully!!

Never noticed improved performance mind, but around town I guess you don't?

My unqualified advise would be to bare with it, get some miles in it, which will build the carbon layers and muffle it somewhat.... Failing that you can always remove it for a mild steel jobby!

I'm not sure who defines the rules for N.I., but the UK rules recently changed to include two reasons for failure, which are "A catalytic converter missing where one was fitted as standard." and "A silencer in such condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a standard silencer in average condition." So cars which have been de-catted are likely to fail future MOTs. Not trying to be smart, just stating that you might want to take this into account before buying a new exhaust system that you might have to remove at the next MOT.

BTW I'm not against loud exhausts - it took me 12 months to stop looking for the motorbike that kept following behind my other car.

I read through the Driver Vehicle Agency light vehicle testers manual before I removed the cat and found this.

Check for the presence of a catalytic converter on spark ignition engined vehicles first used on or after 1 July 2002 with, four or more wheels, a GVW of more than 400kg, not more than 12 passenger seats, and a DGW of not more than 3500kg.

saddle bags wrote:I read through the Driver Vehicle Agency light vehicle testers manual before I removed the cat and found this.

Check for the presence of a catalytic converter on spark ignition engined vehicles first used on or after 1 July 2002 with, four or more wheels, a GVW of more than 400kg, not more than 12 passenger seats, and a DGW of not more than 3500kg.

the internet is a wonderful thing

Are you sure that this doesn't mean that anything after 01/07/2002 has to have one whereas Robert's quote means that if they had one as standard,whatever year, then they still have to have one. If they were first registered pre 01/07/2002 and did not have one as standard then you don't have to retrofit.

I know where you're coming from with the VOSA site, the thing is the Driver Vehicle Agency (DVA) are the body responsible for delivery of all vehicle testing in Northern Ireland. Things are different over here, our cars are MOT'd at 4 years old, there are only 15 test centers which all vehicles must come to. The DVA only test vehicles they don't carry out any type of work on them, totally independent.

When I got the car tested in Feb the examiner commented about how good the stainless decat pipe looked, and said it was a pity I didn't have re rest of the exhaust to match it

saddle bags wrote:I know where you're coming from with the VOSA site, the thing is the Driver Vehicle Agency (DVA) are the body responsible for delivery of all vehicle testing in Northern Ireland. Things are different over here, our cars are MOT'd at 4 years old, there are only 15 test centers which all vehicles must come to. The DVA only test vehicles they don't carry out any type of work on them, totally independent.

When I got the car tested in Feb the examiner commented about how good the stainless decat pipe looked, and said it was a pity I didn't have re rest of the exhaust to match it

Ok - Thanks for that - I understand now. I thought it was all under a EU directive that we all had to comply with.
Cheers